In a medium bowl, toss the raspberries with the orange liqueur and sugar. Set aside.

Melt the chocolate in a small saucepan set on low heat, then whisk in the mascarpone cheese. Remove from the heat, stir in the orange zest and set aside.

Whip the cream in a large bowl with a thisk or electric mixer until stiff peaks form. (You have reached the stiff peak stage when you lift the whisk or beater from the cream and the top of the peak stands up straight.) Carefully fold the chocolate mixture into the whipped cream one-third at a time.

Spoon half the raspberries into 6 dessert dishes. Spoon the chocolate cream on top and sprinle with the remaining raspberries. Serve immediately.